<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 打印100以内偶数的和 -->
    <script>
        // 先找100以内的偶数
        var sum =0;
        for(var i=1;i<=100;i++){
            if(i%2===0){
               sum+=i;    //sum接收所有偶数之和        
            }                
        }
        console.log(sum);
    </script>
</body>
</html>